Spray applications are used for a variety of coating processes. Some spray application devices include a primary fluid stream into which a coating agent is introduced. The primary fluid stream including the coating agent is directed at a work piece to achieve the desired coating. It is necessary to maintain control over the fluid flow and the introduced coating agent to achieve a desired coating.
One challenge presented in many spray application devices is that build up may occur on the application device components. For example, in thermal spray applications, the coating agent comprises fine particles that can tend to build up on the spray nozzle, powder ports and other spray components. Such build up interferes with proper powder introduction to the primary fluid stream such as a plasma plume. Without proper powder injection, a variation in the coating properties may occur resulting in an imperfect coating on the work piece.